Joint and crack seal and method for sealing joints and cracks



March 31, 1970 9, w, G ;v ETAL 3,503,311

JOINT AND CRACK SEAL AND METHOD FOR SEALING JOINTS AND CRACKS Filed Sept. 26, 1968 INVENTORS D.W.GAGLE I H.L. DRAPER BY (4,14

ATTORNEYS United States Patent 3,503,311 JOINT AND CRACK SEAL AND METHOD FOR SEALING JOINTS AND CRACKS Duane W. Gagle and Homer L. Draper, Bartlesville, Okla., assignors to Phillips Petroleum Company, a corporation of Delaware Filed Sept. 26, 1968, Ser. No. 762,873 Int. Cl. E01c 11/10 US. CI. 94-18 5 Claims ABSTRACT OF THE DISCLOSURE Joints or cracks, e.g., space between concrete slabs are packed employing polypropylene tow saturated with cationic asphalt emulsion. The tow can be saturated before or after it has been placed into the joint or crack. Several layers of tow can be used filling to about A-inch from pavement surface and cationic asphalt emulsion added to bring the packed joint level to about As-inch of the pavement surface. Optionally, the last Az-inch fill can be airblown cut-back asphalt impregnated with about 5 percent asbestos filler. A small amount of cationic asphalt emulsion can be placed into the void between the slabs to prime the bottom area prior to inserting the polypropylene tow. Other asphalt emulsions are disclosed. The adhesiveness of the asphalt mass containing the polypropylene filler is retained through repeated extensions and compressions thereof.

This invention relates to sealing of joints or cracks. In one of its aspects the invention relates to a method for sealing a joint or a crack, e.g., a space between concrete slabs. In another of its aspects the invention relates to a joint produced by the method of the invention.

According to a concept of the invention it provides a joint, for example, between concrete slabs, the joint being packed using polypropylene tow saturated with an asphalt emulsion, preferably a cationic asphalt emulsion. In a further concept of the invention a seal or joint is packed with one or more pieces of polypropylene tow which then is wet with asphalt. In another of its concepts the invention provides a seal or joint packing of one or more pieces of polypropylene tow impregated with asphalt emulsion used to fill to within about At-inch from the pavement surface whereupon asphalt emulsion is then added to bring the packed joint level to about Aa-inch of the pavement surface. In still another of its concepts the invention provides for placing a small amount of asphalt emulsion into the void, i.e., into the bottom of the joint or crack, to prime the bottom area prior to insertion of the polypropylene tow. Further, still according to a concept of the invention, the last %inch or so of fill can be with airblown cut-back asphalt admixed with approximately 5 weight percent asbestos filler.

Conventional materials for sealing expansion joints in concrete pavements and cracks in both asphalt and concrete pavements include hot and cold applied bituminous mastics, rubber compounds, coal tars, asphalts, and various combinations of these materials with and without minerals fillers and polymers.

Satisfactory sealers must have highly adhesive properties to eifectively bond on both sides of the joint or crack and not pull away when subjected to repeated cycles of contraction and expansion. Additional properties required are toughness, flexibility and resilience over a wide range of temperatures and conditions of usage.

The problem of eifectively sealing joints and cracks in pavements has persisted since the inception of roads. Engineers, chemists, technicians and manufacturers have yet to develop a material that is completely satisfactory in every respect.

We have conceived an improved method which not only meets the requirements of effective sealers, but has the added advantages of simplicity, low cost of installation and durability.

Thus, we have conceived that polypropylene tow and asphalt emulsion work well as a sealer or joint filler. This combination has the desired properties above set forth. Thus, after a joint or crack has been suitably cleaned by conventional means, it can be sealed by insertion thereinto of polypropylene tow impregnated with asphalt emulsion. In one embodiment of the invention, the crack or joint is first primed with a small quantity of asphalt emulsion, the polypropylene tow impregnated with additional quantities of asphalt emulsion is worked into the joint or crack space and followed with additional asphalt emulsion to act as a top sealing coat. In another embodiment a layer of asphalt containing a filler such as asbestos filler is used to cover the joint.

It is an object of this invention to provide a method for sealing joints or cracks. It is another object of this invention to provide a method for flexibly and resiliently filling a void between two objects which move when subjected to temperature changes. It is a still further object of this invention to seal joints or cracks in cement and/ or asphalt pavements. It is a still further object of this invention to provide a novel combination of materials for flexibly and resiliently sealing a space as in a road joint or crack. A still further object of the invention is to provide a novel joint or seal.

Other aspects concepts and objects of the invention are apparent from a study of this disclosure, the drawing and the appended claims.

According to the present invention a joint or crack is filled with sealing materials substantially as follows: A small quantity of cationic asphalt emulsion or equivalent is poured into the void to prime the bottom area. The void is then packed, building up from the bottom thereof with polypropylene tow which has been presaturated with asphalt emulsion, preferably with cationic asphalt emulsion. The void is thus filled to within approximately flz-inch from the surface of the road or pavement or other object. Following this, cationic asphalt emulsion or equivalent is poured over the packing to within approximately As-inch from the pavement surface. This provides a top seal and allows clearance to prevent tracking by objects moving over the seal.

Also according to the invention a small amount of cationic asphalt emulsion can be poured into a void to prime the bottom area, following which a rope-like twist of dry polypropylene tow is worked into the void using a caulking tool if desired or other suitable packing device. Then a small amount of cationic asphalt emulsion or other equivalent fluid is poured over the packing. The insertion of the tow and the pouring of the asphalt emulsion or equivalent fluid can be repeated until the void is filled to approximately fli-inch from the pavement surface. Then cationic asphalt emulsion or equivalent is poured over the packing to within approximately Az-inch of the pavement surface.

Still according to the invention the final small portion approximately As-inch, for example, of the seal can be made with airblown cut-back asphalt mixed with approximately 5 percent by weight of asbestos filler, for example, type JM-7M-02. This will improve the weather resistance, increase the flow resistance of the asphalt during the exposure to high temperatures and reduce brittleness during cold weather.

EXAMPLE A joint 25 feet long is filled using 9 grams of polypropylene tow, 81 grams, 0.0215 gallon of cationic asphalt emulsion per linear foot. Thus, one pound of polypropylene tow and 1.1 gallons of cationic asphalt emulsion,

3 type RS-ZKH effectively seals a joint /z-inch Wide, 2 inches deep and 25 feet long.

The polypropylene tow and asphalt emulsion can be very simply inserted into the joint. Thus, it is noted especially that the new methods of our invention do not require specialized equipment, such as heating kettles, pressure injectors, grouting tools, etc. The asphalt materials and the polypropylene tow can be and are applied at relatively low temperatures, for example, 65100 F.

Referring now to the drawings, there is illustrated the filling of a joint between two concrete blocks 1 and 2. In FIGURE 1, there is shown the blocks and therebetween at the bottom of the joint asphalt primer. FIGURE 2 shows the joint filled with polypropylene tow and additional asphalt emulsion and FIGURE 3 shows the filled joint with the asphalt seal over the filling in the joint. Numeral 3 represents the asphalt primer; numeral 4 represents the asphalt-saturated polypropylene tow; and numeral 5 represents the top coating of asphaltic material.

The inventive concepts set forth herein are based, at least in part, upon the excellent properties of polypropylene tow and its coaction with the asphalt emulsion, preferably cationic asphalt emulsion, as described herein.

The value of this invention over, say, the use of glass fibers can be made evident as follows.

Glass fibers which are used are usually available in a bulk mass. It is necessary for the operator to pull off chunks of glass fibers and to stuff these into the crack to be patched. This method does not give a true continuous piece of filling material and it is diificult to control to a uniform density of filling. Further, glass fiber is difiicult to handle and requires protective gloves for the operator. Some persons develop tremendous rashes due to allergy to glass fiber. It takes about four times as long to install glass fibers as it does to insert the polypropylene tow. Per contra, polypropylene tow is a continuous rope-like material and can be cut to proper lengths to be easily installed as a continuous piece of filling material. It can be handled easily without gloves. There is no allergy problem. The polypropylene tow is flexible even down to about 40 F. The brittleness of fiber glass, even at relatively elevated temperatures, is well known. Polypropylene tow has the excellent affinity for asphalt already inferred.

In actual use it has been found that contractors on certain jobs have preferred the method of the present invention over the method which results in a fiber glass packed joint or seal.

It has been found that the polypropylene filler con taining asphalt seal retains its adhesiveness through repeated extendings or extensions and compressions thereof within a joint or crack.

It is within the scope of the present invention to use various asphalts and emulsions, all of with which the polypropylene tow will coact, based upon its properties, to yield a superior joint and crack seal.

Reasonable variation and modification are possible within the scope of the foregoing disclosure, drawings and the appended claims to the invention the essence of which is that there has been provided a new method for producing a joint or crack seal and a new joint or seal substantially as described herein, based upon the use of polypropylene tow and asphalt emulsion, in a preferred form of the invention the joint or crack to be sealed being primed with a small quantity of asphalt emulsion, the polypropylene tow and more asphalt emulsion being added into the joint or crack and the hole being sealed off with additional asphalt emulsion and/ or airblown cutback asphalt containing a mineral filler such as asbestos.

We claim:

1. A method for filling a joint or crack between two segments of solid material subject to expansion and contraction with change in temperature which comprises filling said joint or crack with polypropylene tow impregnated with an asphalt emulsion.

2. A method according to claim 1 wherein the joint or crack is primed with asphalt emulsion, the polypropylene tow and additional asphalt emulsion are added to seal the joint.

3. A method according to claim 1 wherein the top of the joint or crack is sealed employing asphalt which has been airblown cut-back and which contains a mineral filler such as asbestos.

4. A method according to claim 1 wherein dry polypropylene tow is packed into said joint or crack and then the asphalt emulsion is poured over the packing.

5. A method according to claim 1 wherein the polypropylene tow is preimpregnated with the asphalt emulsion when it is placed into said joint or crack.

References Cited UNITED STATES PATENTS 2,220,444 11/1940 Gisslander 94-18 3,334,557 8/1967 Fitzgi'bbon 94-18 JACOB L, NACKENOFF, Primary Examiner 

